1. Field of the Invention
The present invention relates to a relay system between relative rotation members for performing an electric connection between two members rotating relatively to each other, and particularly relates to a relay system between relative rotation members having a mechanism for temporarily fixing two members rotating relatively to each other.
2. Related Art
As a relay system between relative rotation members of this type, for example, known is that which is disclosed in Japanese Patent Unexamined Publication No. Hei-7-282935. The relay system between relative rotation members disclosed in this publication has first and second rotors rotating relatively to each other, in which the first rotor is provided with a lock mechanism and the second rotor is provided with a lock recess portion.
The lock mechanism has its top end portion which may be fitted into the lock recess portion to prohibit the relative rotation between the first rotor and the second rotor. The movement of the lock mechanism is restricted by a detent mechanism to thereby keep the state in which the top end portion is fitted in the lock recess portion.
In addition, a direct connector is provided in the first rotor. The lock mechanism is moved by an external connector so as to be connected to this direct connector and the top end portion of the lock mechanism is detached from the lock recess portion so as to enable the relative rotation between the first rotor and the second rotor.
However, in the above-mentioned relay system between relative rotation members, the lock mechanism was constituted by a separate body different from the first rotor, and the detent mechanism for restricting this lock mechanism was required. Accordingly, the number of parts was large, and the structure was complicated. Therefore, there were problems in workability of assembling and in cost.